Don't understand the reason for "Expected a type" compilation error in a method declaration, when the type is defined

Question

This code won't compile and generates the error message "Expected a type". As the type is declared right above I don't understand why.

enum TMyType
{
    Etype1,
    Etype2
};

@interface Factory : NSObject

+ (void) foo: (TMyType) actionType;

@end

Answer 1

To define a custom type, the correct way is with a typedef.

Try...

typedef enum 
{
    Etype1,
    Etype2
} TMyType;

EDIT: Not long after this question was asked and answered, Apple came out with a new way to do enumerated data types. Here's an in-depth article on it.

typedef NS_ENUM(NSInteger, TMyType) {
    Etype1,
    Etype2
};

Answer 2

+ (void) foo: (enum TMyType) actionType;

or use .mm (and retag question with objective-c++).